title: A comparison in adolescents of composite auditory evoked potential index and bispectral index during propofol-remifentanil anesthesia for scoliosis surgery with intraoperative wake-up test.
abstract: BACKGROUND
  The electroencephalogram-derived Bispectral Index (BIS), and the composite A-line ARX index (cAAI), derived from the electroencephalogram and auditory evoked potentials, have been promoted as anesthesia depth monitors. Using an intraoperative wake-up test, we compared the performance of both indices in distinguishing different hypnotic states, as evaluated by the University of Michigan Sedation Scale, in children and adolescents during propofol-remifentanil anesthesia for scoliosis surgery. Postoperative explicit recall was also evaluated.
  
  
  METHODS
  Twenty patients (aged 10-20 yr) were enrolled. Prediction probabilities were calculated for induction, wake-up test, and emergence. BIS and cAAI were compared at the start of the wake-up test, at purposeful movement to command, and after the patient was reanesthetized. During the wake-up test, patients were instructed to remember a color, and were then interviewed for explicit recall.
  
  
  RESULTS
  Prediction probabilities of BIS and cAAI for induction were 0.82 and 0.63 (P < 0.001), for the wake-up test, 0.78 and 0.79 (P < 0.001), and 0.74 and 0.78 for emergence (P < 0.001). During the wake-up test, a significant increase in mean BIS and cAAI (P < 0.05) was demonstrated at purposeful movement, followed by a significant decline after reintroduction of anesthesia.
  
  
  CONCLUSIONS
  During induction, BIS performed better than cAAI. Although cAAI was statistically a better discriminator for the level of consciousness during the wake-up test and emergence, these differences do not appear to be clinically meaningful. Both indices increased during the wake-up test, indicating a higher level of consciousness. No explicit recall was demonstrated.
authors.affiliation: Department of Anesthesiology, Erasmus Medical Center, Dr. Molewaterplein 60, 3015 GJ Rotterdam, The Netherlands. h.blussevanoudalblas@erasmusmc.nl
authors.forename: Heleen J
authors.initials: HJ
authors.lastname: Blussé van Oud-Alblas
authors.forename: Jeroen W B
authors.initials: JW
authors.lastname: Peters
authors.forename: Tom G
authors.initials: TG
authors.lastname: de Leeuw
authors.forename: Kris T A
authors.initials: KT
authors.lastname: Vermeylen
authors.forename: Luuk W L
authors.initials: LW
authors.lastname: de Klerk
authors.forename: Dick
authors.initials: D
authors.lastname: Tibboel
authors.forename: Jan
authors.initials: J
authors.lastname: Klein
authors.forename: Frank
authors.initials: F
authors.lastname: Weber
mesh_terms: D000293:Adolescent; D000328:Adult; D018686:Anesthetics, Intravenous / Q000627:therapeutic use; D002648:Child; D004569:Electroencephalography / Q000379:methods*; D005072:Evoked Potentials, Auditory / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D016343:Monitoring, Intraoperative / Q000379:methods*; D010880:Piperidines / Q000627:therapeutic use*; D011237:Predictive Value of Tests; D011336:Probability; D015742:Propofol / Q000627:therapeutic use*; D000077208:Remifentanil; D012600:Scoliosis / Q000601:surgery*; D014851:Wakefulness / Q000187:drug effects / Q000502:physiology*
chemical_list: D018686:Anesthetics, Intravenous; D010880:Piperidines; D000077208:Remifentanil; D015742:Propofol